Recently, there has been much development in the field of embedded devices adapted to be connected to the Internet or similar. An embedded device is generally in the form of a microcontroller or the like adapted to interact with a larger server or servers, thereby allowing a device (such as a vending machine, domestic electric appliance, motor vehicle etc) to be remotely controlled and/or monitored from a central server by way of a standard protocol such as Internet Protocol. A major difficulty with embedded devices is that they generally comprise microcontrollers or the like with very limited RAM and ROM. Communicating embedded devices are often required to take part in client-server transactions with complex permission and billing relationships. A typical microcontroller for use as an embedded device may have 32 kB of ROM and 1 kB of RAM, which is not enough to support the usual client-server protocols such as SOAP (Simple Object Access Protocol) or CORBA (Common Object Request Broker Architecture). The characteristics of these devices are such that conventional implementations (such as those described in Gary R Wright and W Richard Stevens, “TCP/IP Illustrated Volume 2: The Implementation”, Addison-Wesley Professional Computing Series, 1995) of Internet Protocols (“IP”) and the layered protocols such as Transmission Control Protocol (“TCP”) or User Datagram Protocol (“UDP”), as well as higher-level application protocols such as HTTP, FTP, Telnet etc. are not feasible as they would demand more RAM or ROM than is typically available on the device. Embodiments of the present invention seek to provide techniques that enable such restricted devices to take part in complex permission and billing relationships and to interact with relational databases.
Techniques for enabling feature-rich communication to and from embedded devices are discussed in more detail in the present applicant's UK patent application no 0116549.7 entitled “Improvements relating to reduction of resource usage in TCP/IP implementation”, the full disclosure of which is hereby incorporated into the present application by reference.